A problem with an engineering train between London Blackfriars and London St Pancras International means that some lines are currently closed.
Trains running between these stations may be delayed by up to 30 minutes or revised as a result of this.
Disruption is expected to continue until 08:00.
Customer advice:
If you are travelling now, your journey may take up to 30 minutes longer than usual.
Please check journey planners and station information boards before you travel, and allow extra time to reach your destination.
Live departure boards can be found here, and you can check the live map here to see if your journey has been affected.
You can also use the Thameslink app to find up-to-date travel information.
Can you tell me more about the incident?
At the moment, Thameslink are working with local staff and colleagues at Network Rail to assess the situation.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner.
Compensation:
You may be entitled to compensation if you experience a delay in completing your journey today. Please keep your train ticket and make a note of your journey, as both will be required to support any claim.